Medical devices, such as catheter systems, are well known in the art for use in medical procedures, such as diagnostic (e.g., cardiac mapping) and therapeutic procedures (e.g., cardiac ablation). Typical catheter systems generally include an elongated flexible catheter shaft extending from a control handle containing an actuating mechanism. A physician manipulates the catheter shaft through the patient's vasculature to an intended site within the patient via the actuating mechanism contained within the control handle.
An actuating mechanism of the catheter system may include mechanical steering features or components that may be manually manipulated to position a catheter shaft within the body at a desired site or to operate the catheter system during use. In some embodiments, a catheter or catheter system may be positioned within a patient's vasculature during a procedure by simultaneous application of torque or force at the proximal end of the catheter and/or by selectively deflecting the distal tip of the catheter in a desired direction.
The distal tip of the catheter can be deflected by a pull wire or other tension member attached or anchored at the distal end of the catheter and extending proximally to an actuator in a control handle that controls the application of tension on the pull wire. Distal movement of the catheter shaft with respect to a body of the control handle, upon the application of an external force on the actuating mechanism, may impose eccentric pull forces on the distal portion of the catheter shaft resulting in the distal portion of the catheter shaft assuming a deflected configuration. Absent an external force exerted on the actuating mechanism, the catheter shaft tends to return to its natural, unstressed position due to the force exerted on it by the strained pull wire.